The New Strategic Arms Reduction Treaty - or START - recently signed between the United States and Russia deals only with long-range nuclear weapons. Our correspondent looks at whether the next round of arms negotiations might deal with short-range nuclear weapons.

The New START Treaty sets a limit of 1,550 deployed strategic - or long-range - nuclear warheads. Those are the ones mounted on top of intercontinental ballistic missiles fired from underground silos. Long-range missiles are also delivered from heavy bombers or submarines.

the new treaty does not address is the issue of tactical - or short-range - nuclear weapons including land and air-based missiles with a range of less than 500 kilometers - so-called "battlefield weapons" used alongside conventional forces.

Daryl Kimball, Executive Director of the Arms Control Association, a private research firm, says Moscow has a far greater number of such weapons than Washington.

"The United States has several hundred gravity bombs - these are air-dropped bombs - about 200 of these are believed to still be in Europe at five NATO bases. Russia has, by various estimates, some two to 4,000 tactical nuclear bombs, but not all of these are available for operational use. Many are awaiting dismantlement, many are in deep storage bunkers - so it's not clear how many they have," said Kimball.

Experts say the NATO weapons are located in Belgium, Holland, Germany, Italy and Turkey. Many of Russia's missiles are housed in the western part of the country.

David Holloway, an arms control expert at Stanford University, explains why Russia has such a vast superiority.

"The argument is this - that Russia's conventional forces are very weak and therefore it needs tactical nuclear weapons to compensate for the weakness of its conventional forces vis-à-vis NATO on the one hand or vis-à-vis any other country, especially - although it is not really much discussed in public - especially against China," he said.

But Frank Miller, former senior official on the National Security Council, under President George W. Bush, doesn't buy the Russian argument.

"How the Russian government can justify having an obscene number of short-range nuclear weapons which number three to four to 5,000 escapes imagination," he said. "And this is something which needs to be justified to the global community. And it can't be because NATO threatens Russia with conventional military force. Because if you look at the alliance's conventional military forces, the numbers of our forces in Europe are very small - and the notion that [28 NATO] allies would get together and decide to attack Russia is absolutely absurd on the face of it."

Many experts believe the tactical weapons on both sides are a relic of the Cold War and have little or no military value.

But Frank Miller says those weapons do play a crucial role.

"They have had an extremely important political value not only in deterring war but in reassuring our NATO allies over the decades that the United States is fully committed to the defense of the alliance and to the territorial integrity of all alliance states," said Miller. "And that is the purpose that they continue to serve."

Experts, such as David Holloway from Stanford University, say there is an internal debate within NATO regarding what to do with those short-range nuclear weapons.

"Some NATO countries would like to see the tactical nuclear weapons removed from Europe - but some NATO countries apparently don't want to see them removed," said Holloway. "And the U.S. position has been that it's quite willing to remove these weapons from Europe, but only if the NATO allies want that done. And there isn't a consensus within NATO on that."

Many experts say the next round of arms control negotiations between Washington and Moscow might involve the issue of tactical nuclear weapons in Europe. But Russia has rejected such talks in the past.

And former U.S. Ambassador to the United Nations and arms control expert John Bolton doesn't see the Russians changing their position anytime soon.

"Why should they agree to anything that would bring them down to the very, very insignificant levels of tactical nuclear weapons that we still have in Europe?" he asked.

Analysts say before there is any talk of new arms control negotiations between Washington and Moscow, the U.S. Senate and the Russian Duma must first ratify the new START treaty cutting long-range nuclear weapons. Experts say ratification of that treaty could serve as an impetus to further talks on reducing nuclear weapons.